1. Field of the Invention
The present invention relates generally to catheters and more particularly, to a multi-lumen catheter with an increased flow area (e.g. increased cross-sectional area of the lumen/s for increasing the flow rate capabilities of the catheter) and a method for making the multi-lumen catheter.
2. Background of the Invention
Catheters for the introduction or removal of fluids may be positioned in various venous locations and cavities throughout the body of a patient for introduction of fluids to the body or removal of fluids from the body. Such catheterizations are often performed using a catheter with multiple lumens. Examples of such catheters are central venous catheters which are typically used for medical procedures such as blood pressure monitoring, blood sampling and the administration of drugs, diagnostic materials and fluids to a patient. These procedures often require that the catheter have sufficiently sized lumens for providing therapeutic and/or diagnostic treatments, such as for example, administering fluids to the patient or withdrawing/removing fluid (e.g. body fluids or otherwise) from the patient.
Generally, a central venous catheter is surgically inserted into a vein, such as the basilica, cephalic, subclavian, or jugular, with the distal tip of the catheter residing in the superior vena cava. These catheters are typically introduced using percutaneous entry techniques, such as the well-known Seldinger technique. In the Seldinger technique, the physician makes an oblique entry into the vein with a beveled needle. A wire guide is then inserted through the bore of the needle about 5 to 10 centimeters into the vein. The needle is thereafter withdrawn, leaving the wire guide in place. The catheter is then inserted over the wire guide, and advanced through the skin at the needle puncture site and into the vein. The Seldinger technique can be modified to include a peelable introducer which can be used to dilate the body vessel. In particular, the introducer sheath can be placed over the wire guide, and after removal of a dilator, the catheter can be placed through the sheath for insertion into the patient. In either of these procedures, the catheter is preferably sized such that the outer diameter (e.g. relatively small outer diameter) facilitates introduction of the catheter through the skin and into the vein without occluding the vein. Once the catheter is in place within the vein, the wire guide is withdrawn and therapeutic treatment using the catheter can begin. Preferably, the catheter has sufficient flow area (e.g. relatively large flow area) for each of its lumens for providing various treatments to the patient, such as for example, during infusion therapy. At the conclusion of the therapeutic treatment, the catheter is withdrawn from the patient. Preferably, the outer diameter of the catheter is configured (e.g. relatively small outer diameter) to facilitate the catheter being withdrawn from the patient. Currently available multi-lumen catheters with relatively large inner diameter lumens and currently available multi-lumen catheters with relatively small outer diameter shafts result in two diametrically opposed multi-lumen catheter constructions. That is, multi-lumen catheters with relatively large inner diameter lumens have corresponding relatively large outer diameter shafts and multi-lumen catheters with relatively small outer diameter shafts have corresponding relatively small inner diameter lumens.
Accordingly, it may be desirable to have a multi-lumen catheter with increased flow area for providing treatment to a patient while having a relative small outer diameter for facilitating insertion into and/or withdrawal from the patient.